1 00:00:12,95 --> 00:00:16,07 There's two talks that are that you're going to see today we're going to see 2 00:00:16,08 --> 00:00:21,01 a talk by first by Meghan gams who is 3 00:00:21,05 --> 00:00:25,72 a researcher in the oceanography department at here at the University of Washington 4 00:00:26,29 --> 00:00:32,94 and she talks about how the Missoula floods during the coming out of the last ice 5 00:00:32,95 --> 00:00:39,31 age the role that they played in affecting not only the ocean 6 00:00:40,03 --> 00:00:45,04 salinity but also that that effect that those floods had on the. 7 00:00:46,67 --> 00:00:51,58 Atmosphere and and the climate and so the longer term impacts and then I'm going to 8 00:00:51,62 --> 00:00:52,17 take you out of 9 00:00:52,18 --> 00:00:55,67 a talk as well and take you really far back in time and I want to talk about. 10 00:00:57,84 --> 00:01:02,43 Snowball Earth which is this idea that during the neo protozoa which is the time 11 00:01:02,44 --> 00:01:07,56 period about six hundred eight hundred million years ago that the Earth's oceans 12 00:01:07,57 --> 00:01:12,34 work completely covered with ice everywhere and so this is 13 00:01:12,35 --> 00:01:17,96 a very exotic kind of idea but there's some strong evidence for it we seek to 14 00:01:17,97 --> 00:01:24,38 understand it not only the changes that are happening. Right now and that are going 15 00:01:24,39 --> 00:01:29,68 to the future that are being forced by changes were making so we're putting in 16 00:01:29,72 --> 00:01:34,42 carbon dioxide in the atmosphere and that's having an effect on our climate but 17 00:01:34,59 --> 00:01:39,48 what's actually interesting as well is the internal dynamics of the climate system 18 00:01:39,49 --> 00:01:44,80 so what is the earth capable of experiencing in its range of climates just on its 19 00:01:44,84 --> 00:01:48,60 own with out these kind of external forcings and I think those are interesting 20 00:01:48,61 --> 00:01:53,61 questions too so it to be able to understand and I think you have to be able to 21 00:01:53,62 --> 00:01:59,53 understand what. You know what what the what the climate of the future will look 22 00:01:59,54 --> 00:02:04,11 like you really have to understand what the range of the variability of the climate 23 00:02:04,12 --> 00:02:11,08 is. Under its own under under the Earth's own internal processes that are just 24 00:02:11,09 --> 00:02:18,00 going on so. These two talks are more about. These these 25 00:02:18,01 --> 00:02:24,17 these have some forcings which are. You know not anthropogenic in nature but are 26 00:02:24,80 --> 00:02:31,74 processes that. Caused by long term geologic. Processes 27 00:02:31,75 --> 00:02:38,13 So for example the Missoula floods are caused well were caused by 28 00:02:38,66 --> 00:02:42,20 the earth coming out of the Ice Age And so as the earth is coming out of its ice 29 00:02:42,21 --> 00:02:47,01 age things are warming up and water liquid water is starting to melt and it builds 30 00:02:47,02 --> 00:02:49,00 up in these big lakes and it turns out that there was 31 00:02:49,01 --> 00:02:55,96 a big lake near modern day Missoula Montana that. Was damned at one 32 00:02:55,97 --> 00:02:57,52 in by basically 33 00:02:57,53 --> 00:03:03,54 a giant chunk of ice OK so it's an ice we call an ice dam and that ice dam is 34 00:03:03,58 --> 00:03:07,54 inherently unstable it's warming and it's going to be melting and eventually that 35 00:03:07,55 --> 00:03:10,56 dam fails and when that dam fails it releases 36 00:03:10,92 --> 00:03:17,09 a tremendous amount of water into what is now eastern Washington 37 00:03:17,55 --> 00:03:24,08 and. And that's and that water actually carves out 38 00:03:24,09 --> 00:03:30,40 a significant portion of the lower Columbia River. And then in my talk I'm talking 39 00:03:30,41 --> 00:03:37,17 about snowball earth so snowball earth is. Probably cause it's 40 00:03:37,26 --> 00:03:41,47 unknown exactly what caused the snowball earth but I think that it probably is due 41 00:03:41,48 --> 00:03:47,16 to changes in the configuration of the continents and also has to do with the fact 42 00:03:47,17 --> 00:03:50,29 that our. Our sun at that time was 43 00:03:50,30 --> 00:03:56,68 a little dimmer and so. Yeah how can we understand the mechanisms of the climate 44 00:03:57,06 --> 00:03:59,09 so I think I think what Megan is doing is 45 00:03:59,10 --> 00:04:03,70 a terrific climate experiment so what she's kind of doing is seeing well what 46 00:04:03,71 --> 00:04:09,92 happens if you have you know what is essentially the amount of fresh water that is 47 00:04:09,96 --> 00:04:15,00 about the size of one of the one of the great lakes like Lake Superior. If that 48 00:04:15,04 --> 00:04:20,66 enters into the ocean instantaneously so the oceans very salty OK And actually you 49 00:04:21,50 --> 00:04:25,32 can actually And so what that means is that when you add that fresh water to it 50 00:04:25,62 --> 00:04:26,40 you're freshening up 51 00:04:26,41 --> 00:04:31,93 a tremendous amount of water in the ocean instantaneously and the ocean depends on 52 00:04:31,97 --> 00:04:38,17 its saltiness in order to to mix so when you freshen up this water it allows it 53 00:04:38,18 --> 00:04:39,42 allows mixing to happen in 54 00:04:39,43 --> 00:04:44,28 a kind of an unprecedented rate but it is fairly restricted but what she's able to 55 00:04:44,29 --> 00:04:51,11 see is that even these the single event of the Missoula flood has can have lasting 56 00:04:51,12 --> 00:04:56,56 impact for years on the Earth's climate system and so we've seen other systems like 57 00:04:56,57 --> 00:04:59,01 this you know there's a options 58 00:04:59,02 --> 00:05:05,62 a volcano which you know can actually dramatically impact. The Earth's 59 00:05:05,73 --> 00:05:11,95 Earth's earth's weather on the on the timescale of years to even decades. And 60 00:05:11,96 --> 00:05:15,73 that's just single events and so but I think you know 61 00:05:15,74 --> 00:05:19,60 a lot of big question that people have when they when we talk about climate change 62 00:05:19,64 --> 00:05:23,02 is people always ask well is that is this 63 00:05:23,03 --> 00:05:29,60 a natural system or is this a is this actually an anthropology or 64 00:05:29,61 --> 00:05:34,67 a human caused thing that we're doing and so what we do is climate researchers 65 00:05:34,68 --> 00:05:40,75 we're trying to discover and determine what are the 66 00:05:40,76 --> 00:05:46,19 natural. What are what are the natural scenarios that are out there so what could 67 00:05:46,20 --> 00:05:51,80 we achieve with climate change or what could we achieve. Without without these 68 00:05:51,81 --> 00:05:56,70 anthropogenic forcings and then what we do is we see as what we seeing any 69 00:05:56,74 --> 00:06:01,76 different from that and I think that the answer is yes so we are seeing climate 70 00:06:01,77 --> 00:06:08,58 change that is different from any kind of natural forcings that we can give Ok so 71 00:06:08,59 --> 00:06:13,11 we kind of we can kind of understand what the forcings are from volcanic eruptions 72 00:06:13,12 --> 00:06:18,85 we we understood. And what the forcings are variations in the sun's intensity so 73 00:06:18,86 --> 00:06:25,84 the sun. The sun is slightly less and get slightly more intense slightly brighter 74 00:06:26,02 --> 00:06:27,46 and slightly dimmer over about 75 00:06:27,47 --> 00:06:33,85 a ten year timescale and we understand the phenomena so yeah but I think it's I 76 00:06:33,86 --> 00:06:38,23 think it's really important to be able to understand what the earth's climate is 77 00:06:38,28 --> 00:06:43,25 the climate system is capable of on its own before we start making predictions 78 00:06:43,46 --> 00:06:48,51 about where that climate system is heading under this external influence of adding 79 00:06:48,52 --> 00:06:53,54 carbon dioxide to the atmosphere you know before I get started I just wanted to get 80 00:06:53,87 --> 00:06:57,21 all of my acknowledgments out of the way so I want to think the engaged program for 81 00:06:57,22 --> 00:07:01,11 letting me do this as well as town hall and the National Science Foundation who 82 00:07:01,12 --> 00:07:05,59 funds my research along with both of my advisers land THOMPSON And Susan how to who 83 00:07:05,60 --> 00:07:08,89 have the grant through the National Science Foundation I mean the school of 84 00:07:08,90 --> 00:07:12,17 oceanography at the University of Washington which is under the umbrella of the 85 00:07:12,18 --> 00:07:18,15 College of the environment and I'm part of the program on climate change so today 86 00:07:18,16 --> 00:07:21,68 I'm going to talk to you about water rocks in the tropics and try to answer the 87 00:07:21,69 --> 00:07:27,56 question did the Missoula floods impact climate. But before I get started with that 88 00:07:28,06 --> 00:07:28,78 I wanted to give you 89 00:07:28,79 --> 00:07:35,69 a little bit of background on how I got here so. As an 90 00:07:35,70 --> 00:07:40,37 undergrad I studied these microorganisms called for 91 00:07:40,38 --> 00:07:47,12 a minute for us and they tell you looking at the oxygen isotopes of these 92 00:07:47,70 --> 00:07:53,80 you can understand when we have had. Ice Ages in the past 93 00:07:54,100 --> 00:07:58,25 and then I went on and decided that I wanted to study vulcanology because I thought 94 00:07:58,26 --> 00:08:05,20 it was totally cool and kind of exotic so I spent months and months 95 00:08:05,21 --> 00:08:06,61 in the field with 96 00:08:06,62 --> 00:08:10,75 a giant sledgehammer which was incredibly heavy and was out there during hunting 97 00:08:10,76 --> 00:08:17,66 season which was unpleasant but. I got to look at all these really cool old rocks I 98 00:08:17,67 --> 00:08:21,59 got to analyze and I thought that was really interesting but I sort of you know 99 00:08:21,60 --> 00:08:26,58 this is millions of years ago and that's really cool but what happened to climate 100 00:08:26,97 --> 00:08:32,21 when you have these huge volcanic events so I guess so I applied to graduate school 101 00:08:32,38 --> 00:08:36,69 and I'm lucky enough to sort of marry that to looking at catastrophes but not just 102 00:08:36,70 --> 00:08:41,09 at the catastrophe but what are the climatic implications of these catastrophes 103 00:08:44,19 --> 00:08:47,98 and so this is me studying Oceanography in a Gumby suit on 104 00:08:48,21 --> 00:08:53,92 a ship in the middle of the Pacific Ocean and in the middle of the civic ocean we 105 00:08:53,93 --> 00:08:56,20 picked up this rock which is 106 00:08:56,21 --> 00:09:03,01 a Columbia River basalt and it reached the middle of the ocean or 107 00:09:03,02 --> 00:09:08,52 the bottom of the ocean by the missile floods and tell you about today so that this 108 00:09:08,53 --> 00:09:13,43 would be a nice opener. Here's 109 00:09:13,44 --> 00:09:20,34 a map of what the Earth looks like today so you see North America in the center and 110 00:09:20,35 --> 00:09:25,63 all of the white is areas where we have ice sheets or ice so you can see that 111 00:09:25,64 --> 00:09:31,88 there's. Ice in Antarctica and ice over Greenland and around the North Pole 112 00:09:33,80 --> 00:09:39,10 but twenty thousand years ago we were in an ice age so that meant that there was 113 00:09:39,11 --> 00:09:45,06 a lot more ice on land so you can see that the ice extent over Antarctica was much 114 00:09:45,07 --> 00:09:52,07 greater and you see way more ice. Over the northern hemisphere and if you noticed. 115 00:09:54,76 --> 00:10:00,29 The Continent seemed to be bigger during the last ice age and that's because sea 116 00:10:00,30 --> 00:10:06,29 level was lower about four hundred feet lower than it is today so all of our. 117 00:10:07,40 --> 00:10:13,63 Coastlines were much further out there today and that's because all of the water 118 00:10:13,64 --> 00:10:19,18 from the oceans was taken up into these huge ice sheets and these ice sheets were 119 00:10:19,39 --> 00:10:22,95 over a mile high so we're talking 120 00:10:22,95 --> 00:10:27,67 a lot of our youth. So here is 121 00:10:27,68 --> 00:10:32,63 a map of the Pacific Northwest today you can see the outlines of the state and 122 00:10:32,64 --> 00:10:39,58 Seattle as indicated by the yellow star and here is 123 00:10:39,59 --> 00:10:46,47 that. The lowering of sea level and the 124 00:10:46,61 --> 00:10:52,43 extent of our coastline. Expanding during the Ice Age 125 00:10:54,84 --> 00:10:59,08 This is the courtier and ice sheet which is a was 126 00:10:59,56 --> 00:11:05,12 a minor ice sheet on the other side of North America we had the war entire ice 127 00:11:05,13 --> 00:11:10,18 sheet which is this huge ice sheet and because it's very popular in scientific 128 00:11:10,19 --> 00:11:17,10 research climate scientists have found that. During the last glaciation So when 129 00:11:17,32 --> 00:11:22,76 these ice sheets began to melt. Water streaming from the warranty to 130 00:11:22,77 --> 00:11:28,30 a sheet causes dramatic climate change it caused ocean circulation to slow down and 131 00:11:28,31 --> 00:11:32,42 it caused. Changes in climate so 132 00:11:32,43 --> 00:11:38,92 a cooling. Of the atmosphere but not many people have actually 133 00:11:38,93 --> 00:11:40,08 studied the courtier in 134 00:11:40,09 --> 00:11:46,83 a sheet the smaller one on the west coast of North America but this is what I study 135 00:11:47,15 --> 00:11:53,83 so right here is glacially Missoula and glacially is the subject of today's 136 00:11:53,84 --> 00:11:58,99 talk and I wanted to sort of explain what glacially is and sort of 137 00:11:59,00 --> 00:12:03,61 a very schematic way so imagine a depression like 138 00:12:03,62 --> 00:12:06,41 a valley so this is looking from above in 139 00:12:06,42 --> 00:12:12,80 a map field and you have water that sort of pools in this depression or valley 140 00:12:14,44 --> 00:12:20,35 and then along comes a lobe of that corridor. A glacier essentially just 141 00:12:20,36 --> 00:12:24,60 a big glacier and so that it acts as 142 00:12:24,61 --> 00:12:28,59 a dam with this water reservoir building behind it 143 00:12:31,87 --> 00:12:36,46 but then periodically this ice dam fails in some way. 144 00:12:38,82 --> 00:12:43,88 And then all of that water that was built up behind it in this reservoir is able to 145 00:12:44,03 --> 00:12:49,35 flow out very quickly and so here's 146 00:12:49,36 --> 00:12:56,16 a view of the actual valley that the reservoir of glacial existed in 147 00:12:56,60 --> 00:13:03,05 and. That water half the volume of glaciers of Lake Michigan. 148 00:13:04,22 --> 00:13:09,19 Flowed out within an order of hours Think about that so this is 149 00:13:09,54 --> 00:13:16,39 a giant wall of water filled with icebergs and sediment and it's just 150 00:13:16,40 --> 00:13:23,23 rushing out towards the coastline so along the way this very turbulent 151 00:13:23,24 --> 00:13:28,77 water is picking up rocks and it's scouring out the landscape so that's how we get 152 00:13:28,77 --> 00:13:33,79 the scab lands of eastern Washington if you're familiar on your way to. 153 00:13:38,23 --> 00:13:38,62 Unless you're 154 00:13:38,63 --> 00:13:45,80 a husky you know want to go there that's going to do. So but this is. This 155 00:13:45,81 --> 00:13:51,53 is one of those boulders that has been scoured out and you can see how huge that is 156 00:13:51,54 --> 00:13:56,95 and this is being carried by this flood so this is something that is tremendously 157 00:13:56,96 --> 00:14:03,38 catastrophic in fact there's evidence that the the water reached over 158 00:14:03,39 --> 00:14:10,15 a thousand feet high which is about two space needles tall so this is 159 00:14:10,34 --> 00:14:17,23 a huge huge event that's happening very very quickly and recent work from the U.S. 160 00:14:17,24 --> 00:14:23,03 Geological Survey has shown that the floods emptied out through the Columbia River 161 00:14:23,45 --> 00:14:27,27 and into the Pacific Ocean within within an order of weeks of that ice dam 162 00:14:27,28 --> 00:14:34,18 collapsing so this is happening when you think about. The ocean this is 163 00:14:34,19 --> 00:14:36,14 happening basically immediately this is 164 00:14:36,15 --> 00:14:40,33 a fast very very fast event. So there's been 165 00:14:40,34 --> 00:14:45,15 a lot of work looking at where these floods flowed and here's So the black line 166 00:14:45,16 --> 00:14:50,73 sort of shows you where schematically we had these flood events flowing but there 167 00:14:50,74 --> 00:14:53,95 hasn't been a whole lot of work looking at what happens when you all of 168 00:14:53,96 --> 00:15:00,69 a sudden dump all of this fresh water into the Pacific Ocean and that's where our 169 00:15:00,70 --> 00:15:07,25 research comes in and what we ask is what happens when these floods reached the 170 00:15:07,26 --> 00:15:14,23 Pacific Ocean and how can these floods impact limit and to do this we use 171 00:15:14,27 --> 00:15:16,26 a climate model 172 00:15:16,30 --> 00:15:20,84 a computer climate model so this is the same kind of model it's the same model 173 00:15:20,85 --> 00:15:26,19 that's used to understand what the future climate looks like with increasing C O 174 00:15:26,20 --> 00:15:31,03 two into the atmosphere except we're using this model and setting it up so it 175 00:15:31,13 --> 00:15:36,94 simulates what the Earth was like twenty thousand years ago so that going back to 176 00:15:36,95 --> 00:15:43,86 that first photo I had shown the first photo. Of the Ice Age The model has. 177 00:15:45,02 --> 00:15:49,94 Kilometers of ice covering all of the continents and the lower sea level simulate 178 00:15:49,95 --> 00:15:55,57 that So this is what the freshening looks like in our model so Seattle's marked by 179 00:15:55,58 --> 00:16:02,56 the the Black Star and the the blue shape is where we have 180 00:16:02,80 --> 00:16:09,27 said. Where we said this is where the flood happened so the salinity is 181 00:16:09,27 --> 00:16:15,77 decreased so it appears as if we've dumped this fresh water in to the ocean but 182 00:16:15,78 --> 00:16:19,55 before I go on to talk to you about more ocean stuff I kind of wanted to orient you 183 00:16:19,56 --> 00:16:24,03 because it's often complicated to look at the ocean so so far we've been looking at 184 00:16:24,04 --> 00:16:27,100 maps views of everything so that what that where have labeled ocean surface we've 185 00:16:28,01 --> 00:16:32,74 been looking at that that view but now we're going to start looking at what happens 186 00:16:33,15 --> 00:16:38,100 at depth so looking at the side sort of where the fish live and looking at the 187 00:16:39,01 --> 00:16:45,27 actual ocean so to do that we. Sort of takes slices through the ocean 188 00:16:46,14 --> 00:16:50,53 like along this red line and in. In 189 00:16:50,54 --> 00:16:54,37 a vertical section it would look like this so that red line would be there and now 190 00:16:54,38 --> 00:16:56,06 we're looking at it from the side is 191 00:16:56,07 --> 00:17:02,99 a board with that. So 192 00:17:02,100 --> 00:17:07,95 the brown there indicates where we have the continent and so the dark blue is the 193 00:17:07,96 --> 00:17:14,91 ocean and then the lighter blue is the atmosphere and so North is. Heading away 194 00:17:14,92 --> 00:17:21,50 from me on the stage and the equator is closest to me are we still good you guys 195 00:17:21,51 --> 00:17:21,85 respond 196 00:17:21,86 --> 00:17:27,45 a lot more. You're more verbose than many introductory oceanography classes. 197 00:17:29,81 --> 00:17:36,79 So thank you. Well that's possible yeah. So here 198 00:17:36,80 --> 00:17:40,23 is the North Pacific and that's what I was showing you before so we're kind of near 199 00:17:40,52 --> 00:17:45,15 looking at the side view we're close to the Pacific Northwest and then by the 200 00:17:45,16 --> 00:17:51,73 equator that's the tropical Pacific so in side view this is where we've 201 00:17:51,98 --> 00:17:57,29 imposed the freshwater flood and this is what it looks like in the model 202 00:17:58,33 --> 00:18:03,26 so in the left corner you see the picture that I showed you before from the model 203 00:18:03,27 --> 00:18:04,23 and this is looking at 204 00:18:04,24 --> 00:18:09,35 a side view so we freshened the top one thousand meters of the ocean and this is 205 00:18:09,36 --> 00:18:15,47 sort of an intermediate flood event we believe so what we see and so what we see in 206 00:18:15,48 --> 00:18:17,83 the model and what I've drawn for you to make it 207 00:18:17,84 --> 00:18:22,72 a little bit easier to follow is initially there's mixing 208 00:18:24,95 --> 00:18:30,13 and then that mixing changes ocean temperature and we find that on the perimeter of 209 00:18:30,14 --> 00:18:36,07 where we have freshened the North Pacific you get warming on one side and cooling 210 00:18:36,08 --> 00:18:42,78 on the other side and that allows heat to transfer 211 00:18:42,79 --> 00:18:49,15 from the ocean to the atmosphere and when you're transferring heat we 212 00:18:49,16 --> 00:18:56,14 energize the atmosphere. And I'll stop there for 213 00:18:56,15 --> 00:19:00,65 a second and go back and talk to you about the tropical Pacific so keep this in 214 00:19:00,66 --> 00:19:01,78 your mind we'll come back to in 215 00:19:01,79 --> 00:19:05,30 a minute but I want to give you some background on the tropical Pacific because 216 00:19:05,31 --> 00:19:10,71 it's of an incredibly dynamic and fascinating place and you need this background 217 00:19:10,75 --> 00:19:16,36 before we move on to the next part so this is the tropical Pacific Ocean 218 00:19:18,62 --> 00:19:24,51 this is the central the central America South America. Just to orient you 219 00:19:26,03 --> 00:19:31,89 here's the equator five degrees north and five degrees south so those are lines of 220 00:19:31,90 --> 00:19:38,11 constant latitude and this red blob here this is the Western Pacific warm pool 221 00:19:39,53 --> 00:19:46,35 and so this is this warm water mass that is remains at 222 00:19:46,36 --> 00:19:51,49 about eighty four degrees Fahrenheit or about twenty nine degrees Celsius all the 223 00:19:51,50 --> 00:19:56,45 time it's really it's bathwater essentially in terms of warmth 224 00:19:58,71 --> 00:20:03,72 and so that is able to stay near popular New Guinea and Australia by these trade 225 00:20:03,73 --> 00:20:10,58 winds that blow from the east to the west but periodic Lee what 226 00:20:10,59 --> 00:20:17,54 happens is these winds weekend or they reverse direction and head from west to 227 00:20:17,55 --> 00:20:24,19 east which allows this warm pool of water to move towards the 228 00:20:24,23 --> 00:20:30,78 eastern portion of the tropical Pacific and we have 229 00:20:30,79 --> 00:20:36,28 scientists like to quantify that to sort of make measurements about this so what we 230 00:20:36,29 --> 00:20:42,91 do is we look at. The ocean surface temperature in this box 231 00:20:44,10 --> 00:20:49,66 which we call the Nino three point four region and we take the average of all of 232 00:20:49,67 --> 00:20:53,29 the temperatures that we measure in this area between five degrees north and five 233 00:20:53,30 --> 00:20:55,79 degrees south and we come up with 234 00:20:55,80 --> 00:21:00,83 a single value. So the pictures shown here this would be 235 00:21:00,84 --> 00:21:06,96 a lie niña event are you familiar with El Nino and La niña Yeah so during the 236 00:21:07,52 --> 00:21:14,51 event you know you probably wouldn't want to get. Season ski pass here right 237 00:21:14,73 --> 00:21:18,08 so. I'm going to go there. 238 00:21:21,80 --> 00:21:27,20 So and then this would be an El Nino event where you have that warm water in this 239 00:21:27,21 --> 00:21:31,85 box and so here is a map or Here's 240 00:21:31,86 --> 00:21:37,73 a graph that shows the value of the average sea surface temperature in that region 241 00:21:37,97 --> 00:21:44,69 through time so you can sort of by I pick out some big events 242 00:21:44,81 --> 00:21:50,08 some warm times like the in one thousand nine hundred eighty three on the new event 243 00:21:51,36 --> 00:21:53,95 and the one thousand nine hundred seven one thousand nine hundred eight event I 244 00:21:53,97 --> 00:21:58,15 remember that one particularly because I remember being stuck at school until 245 00:21:58,17 --> 00:22:02,31 midnight because the entire neighborhood was flooded and we had to wait for the 246 00:22:02,32 --> 00:22:08,63 fire department to come and take us all home. But this is sort of difficult to look 247 00:22:08,64 --> 00:22:12,82 at because it's sort of difficult to see where the only new events are and where 248 00:22:12,83 --> 00:22:18,72 the La niña events are so what we end up doing is we look at sort of the. The 249 00:22:18,73 --> 00:22:24,77 unusual years the differences from the average And so the red the red regions on 250 00:22:24,78 --> 00:22:28,27 this graph show you when we've had only you know years and the blue tell you when 251 00:22:28,28 --> 00:22:33,81 we have had years so again here's the one thousand nine hundred seven or here's the 252 00:22:33,82 --> 00:22:37,20 one thousand nine hundred eighty two eighty three and then the one thousand nine 253 00:22:37,21 --> 00:22:43,70 hundred seven one thousand and eight new events OK let's go back to this picture 254 00:22:43,98 --> 00:22:50,41 so the atmosphere has been excited by this transfer of heat from the. From our 255 00:22:50,42 --> 00:22:57,25 freshened region and that allows winds to spin up so we call those anomalous winds 256 00:22:57,35 --> 00:23:04,09 but they're just unusual they're different from the norm. And so those winds 257 00:23:04,24 --> 00:23:10,21 are very similar to these weekend trade winds or these reverse direction winds 258 00:23:11,62 --> 00:23:17,39 and what we see with this these anomalous winds is that we see warmer ocean 259 00:23:17,40 --> 00:23:23,62 temperatures and we're actually seeing is El Nino events that are triggered 260 00:23:24,09 --> 00:23:30,58 by Missoula flood events and this is our. 261 00:23:31,64 --> 00:23:36,64 Our version of that graph from the model and this isn't just one simulation this is 262 00:23:36,83 --> 00:23:40,75 a combination of seven different runs that we did with the model where we freshened 263 00:23:40,76 --> 00:23:44,68 at different times in the different years in the model and we still see the same 264 00:23:44,71 --> 00:23:50,21 response that you're getting warming in the tropical Pacific within months of. 265 00:23:51,25 --> 00:23:58,22 Flooding the North Pacific with glacial Eichmanns all that water so 266 00:23:58,50 --> 00:24:04,16 although Lake Odyssey can change climate dramatically for long periods of time we 267 00:24:04,17 --> 00:24:10,59 show that glacial can also change the climate and going back to thinking about the 268 00:24:10,60 --> 00:24:16,65 new online niña you can remember that snow pack is not so great during one of the 269 00:24:16,66 --> 00:24:21,58 new years and you can see that when you have an El Nino event this is 270 00:24:21,59 --> 00:24:27,70 a map where it shows you every place where. Climate is impacted by 271 00:24:27,71 --> 00:24:31,55 a new event so you see. The warm weather in. 272 00:24:34,82 --> 00:24:40,46 In the Pacific Northwest and wet weather. In Southern California 273 00:24:41,55 --> 00:24:45,82 and warm and dry conditions in Australia and pop and Danny and that's often when 274 00:24:45,83 --> 00:24:52,51 you get those horrible forest fires. So what I've shown you is 275 00:24:52,52 --> 00:24:58,64 that the Missoula floods are number one really cool but number two that they did 276 00:24:58,83 --> 00:25:04,93 they do have global impacts which is really interesting and that's. 277 00:25:05,66 --> 00:25:06,54 That's all I have for you. 278 00:25:08,30 --> 00:25:14,92 Thank 279 00:25:15,66 --> 00:25:22,25 you. I'm wondering if you look to me 280 00:25:22,26 --> 00:25:28,95 like. After the flood that it got warmer because of in the 281 00:25:28,96 --> 00:25:31,96 northwest and would do something to the glacier it was there 282 00:25:31,97 --> 00:25:36,07 a positive feedback or feedback or something you know that's something that we want 283 00:25:36,08 --> 00:25:41,42 to think about and start looking into Unfortunately the model we use the ice sheets 284 00:25:41,46 --> 00:25:47,83 are static so they stay the same no matter what's happening to. Like 285 00:25:47,88 --> 00:25:53,56 precipitation or temperature. But the new generation of models will start to have 286 00:25:54,10 --> 00:25:58,45 what we call dynamic ice sheets so that they can change in response to temperature 287 00:25:58,46 --> 00:26:03,70 changes or precipitation changes I guess I guess the bigger question involved in 288 00:26:03,71 --> 00:26:08,29 that is like with climate change is it itself correcting or does it do the other 289 00:26:08,30 --> 00:26:13,57 thing is that. You know that's what we worry about right like it is going to do 290 00:26:13,59 --> 00:26:14,95 something to cause 291 00:26:14,96 --> 00:26:20,70 a positive feedback loop in that it's going to go right yeah yeah 292 00:26:23,27 --> 00:26:26,52 I had a question on your last night there was 293 00:26:26,53 --> 00:26:32,95 a big northern part of the mix there's no other. 294 00:26:34,71 --> 00:26:41,70 Color and I'm wondering what do you know I don't 295 00:26:41,94 --> 00:26:48,51 know. OK. I pulled this from the no website if you can see from the bottom but I. 296 00:26:50,75 --> 00:26:54,34 Those are my advisors who are in the audience you can correct me if I'm wrong but I 297 00:26:54,35 --> 00:27:00,73 thought during years we had wet weather also in the Gulf of Mexico region. 298 00:27:03,34 --> 00:27:08,48 And it's called colder than usual so I'm not sure why it's not the same color as 299 00:27:08,52 --> 00:27:09,92 other things that are getting light and cold. 300 00:27:16,05 --> 00:27:21,59 Thank you very much to short ones OK why does freshening the water increase the 301 00:27:21,63 --> 00:27:27,03 amount of heat put into the atmosphere is it was freezing water right now is it was 302 00:27:27,56 --> 00:27:32,82 hold water right and in these models we're not actually so we haven't set the 303 00:27:32,83 --> 00:27:38,33 temperature to being cold so it's just the ambient temperature of the ocean in the 304 00:27:38,34 --> 00:27:39,29 way that we've set up it was 305 00:27:39,30 --> 00:27:43,66 a model Titian of more water that increases the energy in the atmosphere it's the 306 00:27:43,67 --> 00:27:49,77 addition of water. We're still looking into exactly why that's happening but it has 307 00:27:49,78 --> 00:27:50,00 to do 308 00:27:50,01 --> 00:27:55,23 a lot with the way that we're putting in the freshwater and just. What happens is 309 00:27:55,47 --> 00:28:01,74 you're having. Constant constant 310 00:28:01,95 --> 00:28:08,81 the pressures it has to do with ocean dynamics in terms 311 00:28:08,82 --> 00:28:14,16 of the when you put in that I call it when you put in this fresh and region it's 312 00:28:14,17 --> 00:28:18,10 not stable it's it has to it some point mixed with the surrounding water and that 313 00:28:18,11 --> 00:28:23,97 means that density surfaces have to change and that so may stop circulation or 314 00:28:23,98 --> 00:28:27,40 something and therefore keep a local more heat in 315 00:28:27,41 --> 00:28:34,01 a local area it's more it's more anomalous heat then yeah yeah 316 00:28:34,60 --> 00:28:41,34 OK And how long did this phenomenon persist was it more than one season or 317 00:28:41,70 --> 00:28:45,82 how many seasons this the only new event seems to happen there was triggered that 318 00:28:45,83 --> 00:28:51,68 was checkered it steams to stick around for up to six months. Or so and now I don't 319 00:28:51,83 --> 00:28:57,47 but we're going so this is just the initial. Connection to the tropics through the 320 00:28:57,48 --> 00:29:02,05 atmosphere and we're starting to look at the model on the longer and longer term 321 00:29:02,06 --> 00:29:08,48 seeing how this freshwater actually moves in the ocean and how that 322 00:29:08,52 --> 00:29:11,66 eventually how that how that affects climate as well. 323 00:29:17,82 --> 00:29:24,82 How big was the volume of water that was released. That caused this event it 324 00:29:24,83 --> 00:29:31,32 was twenty one hundred kilometers cubed I don't know what it is an 325 00:29:31,33 --> 00:29:36,61 imperial you know it's half the volume of of Lake Michigan or about the volume of 326 00:29:37,02 --> 00:29:43,68 Lake Ontario twenty one hundred cubic kilometers and how often did this occur 327 00:29:43,72 --> 00:29:48,31 because there were multiple There were multiple floods so they believe that 328 00:29:48,36 --> 00:29:54,91 initially. The floods who are more infrequent but much bigger so these huge 329 00:29:54,92 --> 00:29:58,86 catastrophic events and then later floods were much smaller so they think that it 330 00:29:58,87 --> 00:30:02,89 could have been hundreds of years between initial floods but then later floods may 331 00:30:02,90 --> 00:30:06,79 have been more frequent on the order of like fifty or twenty five years so that one 332 00:30:06,80 --> 00:30:13,11 more than what what causes the water in the tropical Pacific to always be at 333 00:30:13,12 --> 00:30:15,88 a constant temperature would seem that there must be 334 00:30:15,90 --> 00:30:21,27 a heat source I think you said you went into the you know you know it doesn't 335 00:30:21,28 --> 00:30:24,27 wondering if it's something because it's a sort of 336 00:30:24,28 --> 00:30:29,75 a ring of fire or what what causes that it's more it was so the the water in that 337 00:30:29,75 --> 00:30:32,82 area is all really warm and so maybe that picture made it look like 338 00:30:32,82 --> 00:30:36,57 a two way warmer than surrounding water it's mostly just that that water is always 339 00:30:36,59 --> 00:30:40,48 being heated and it's just being pushed into place and it's sort of staying there 340 00:30:40,49 --> 00:30:45,31 it's not being able to and so it's moved around mostly solar heat solar radiation 341 00:30:45,32 --> 00:30:52,07 that's yeah as in the winds keep employees. What's the relationship of that warm 342 00:30:52,08 --> 00:30:56,69 water trade winds what's causing the trade winds and why are why isn't that 343 00:30:56,70 --> 00:31:01,67 affecting the trade winds or do they somehow draw the trade winds to themselves so 344 00:31:01,68 --> 00:31:08,04 the trade winds are so that has to do with the way the fact that 345 00:31:08,75 --> 00:31:13,66 the Earth is rotating so we just have bands of wind OK that go in certain 346 00:31:13,67 --> 00:31:19,33 directions in that certainly to see those bands go as from east to west. OK Thank 347 00:31:19,34 --> 00:31:26,33 you yeah thanks for questions. With 348 00:31:26,34 --> 00:31:31,62 this interesting model. Are you making your efforts or somebody making efforts to 349 00:31:31,92 --> 00:31:35,34 look at the geologic record to see if some of these predictions actually help with 350 00:31:35,34 --> 00:31:41,55 . Oh in terms of so there's some problems with that so. No 351 00:31:42,35 --> 00:31:44,34 So there's so glacial 352 00:31:44,35 --> 00:31:50,59 a Gaga sea which is the one on the East Coast there ton of there's 353 00:31:50,60 --> 00:31:57,10 a lot of geologic evidence of what happened it's in conjunction with that. The 354 00:31:57,11 --> 00:32:02,66 chemistry of the Pacific Ocean makes it very difficult for foreign minister as like 355 00:32:02,67 --> 00:32:08,56 what I showed you before and other what we call paleoclimate proxy records. Means 356 00:32:08,57 --> 00:32:14,11 of understanding what past climate looked like using like biological things like 357 00:32:14,18 --> 00:32:20,94 form and if they can't survive the record doesn't survive in the Pacific very well 358 00:32:20,95 --> 00:32:27,65 but we've got some in carrier basin and in Santa Barbara basin and shallower areas 359 00:32:27,66 --> 00:32:33,37 but we have something called. The has to do with the acidity of the ocean for 360 00:32:33,38 --> 00:32:37,73 example good look at tree rings in this old rate I did I spoke with somebody at 361 00:32:37,74 --> 00:32:44,29 Colorado State University and. We haven't followed up but he was interested in this 362 00:32:44,30 --> 00:32:45,27 and someone else seems like 363 00:32:45,28 --> 00:32:50,90 a friend yeah and looking at this too you can see that you know other areas are 364 00:32:50,91 --> 00:32:57,65 affected like Southeast Asia and we have records of monsoons. In 365 00:32:57,69 --> 00:33:01,71 southern China and in India and I spoke with somebody from the University of 366 00:33:01,72 --> 00:33:06,02 Toronto and he he was interested in looking at that as well so that is we haven't 367 00:33:06,03 --> 00:33:11,11 done it yet but there may be things just less traditional than what's been used for 368 00:33:11,12 --> 00:33:13,79 a glacial Odyssey but thank you for the question. 369 00:33:23,48 --> 00:33:29,35 Of the night. We know how those floods from the multiple floods were time 370 00:33:29,36 --> 00:33:36,35 correlated. Together. You know I don't I don't know the answer to that I'm 371 00:33:36,36 --> 00:33:42,53 not and I haven't looked at the other floods in much detail but they were all 372 00:33:43,62 --> 00:33:45,16 during this there is 373 00:33:45,17 --> 00:33:49,13 a lot going on if you have one warm year this could happen to it I believe it's 374 00:33:49,14 --> 00:33:52,48 feasible that that would happen that multiple flood would have in the same time and 375 00:33:52,49 --> 00:33:56,20 there even more mega floods there's evidence of mega floods throughout Alaska as 376 00:33:56,21 --> 00:34:02,48 well so it could be much bigger than dismissal. And less. 377 00:34:03,72 --> 00:34:09,93 So yeah OK Yeah thank you for that. Thank you. 378 00:34:13,30 --> 00:34:19,88 I thank you all for coming so I just want to start with this pretty iconic image of 379 00:34:20,64 --> 00:34:27,53 Earth from outer space and to me this this image kind of demonstrates 380 00:34:27,54 --> 00:34:28,92 a lot it demonstrates 381 00:34:29,16 --> 00:34:35,47 a planet that is full of life with this diversity of life over 382 00:34:35,48 --> 00:34:41,90 a lot of different land forms on this image you can see through this and deserts 383 00:34:41,97 --> 00:34:48,93 you can see oceans and land and you can see clouds and ice but it also 384 00:34:48,94 --> 00:34:53,55 suggests something else to me it kind of suggests that Earth is a part of 385 00:34:53,78 --> 00:34:59,08 a greater universe because this is taken from space and it kind of makes you wonder 386 00:34:59,13 --> 00:35:05,33 what else is out there well we've actually been able recently to answer that 387 00:35:05,34 --> 00:35:05,99 question 388 00:35:06,03 --> 00:35:11,29 a little bit and to see some other planets that are outside of our solar system so 389 00:35:11,84 --> 00:35:15,71 I wanted to just start off by looking at some of these strange planets that we've 390 00:35:15,72 --> 00:35:18,88 seen so far this is an artist's rendition of 391 00:35:18,89 --> 00:35:23,20 a planet called co-wrote seventy. Now this is 392 00:35:23,21 --> 00:35:29,40 a planet that's so close to its sun that at over four thousand degrees Fahrenheit 393 00:35:29,95 --> 00:35:34,56 when it rains on this planet it literally rains liquid rock 394 00:35:38,58 --> 00:35:39,34 this is a this is 395 00:35:39,35 --> 00:35:45,90 a funny planet this is called. P one and this is known as the puffy as to planet 396 00:35:45,91 --> 00:35:50,98 that we've found and that's because compared to Jupiter which is the largest planet 397 00:35:51,02 --> 00:35:57,47 in our own solar system it's over twice as wide yet it contains less than 398 00:35:57,48 --> 00:36:02,51 half of the stuff so you can think of this planet as being like a kind of 399 00:36:02,52 --> 00:36:06,14 a giant puffball floating around in space or really kind of like 400 00:36:06,62 --> 00:36:08,36 a marshmallow that's floating around 401 00:36:08,37 --> 00:36:13,58 a campfire for all eternity and this planet is an artist's rendition of Kepler 402 00:36:13,60 --> 00:36:14,83 sixty two F. 403 00:36:15,93 --> 00:36:21,74 This planet is the planet that we think is most likely to have 404 00:36:21,81 --> 00:36:28,78 a life outside of our solar system it's just the right distance from its sun that 405 00:36:28,89 --> 00:36:34,45 it can have vast amounts of liquid water if they're present now here's 406 00:36:34,46 --> 00:36:37,06 a strange planet this is 407 00:36:37,07 --> 00:36:44,04 a planet with land and with oceans but it's 408 00:36:44,05 --> 00:36:50,54 oceans are actually covered in ice and that ice is hundreds of feet 409 00:36:50,55 --> 00:36:51,80 thick as 410 00:36:51,82 --> 00:36:58,42 a matter of fact. So thick that light can't travel through that ice and that I sits 411 00:36:58,43 --> 00:37:05,25 atop the liquid oceans the ice also flows over the 412 00:37:05,26 --> 00:37:09,28 surface like big rivers of ice flowing around the globe 413 00:37:13,11 --> 00:37:16,86 so you might look at this planet and you might say wow this is 414 00:37:16,87 --> 00:37:23,40 a weird planet and it might seem like it's six hundred million miles away but it's 415 00:37:23,41 --> 00:37:29,35 actually six hundred million years away because this is earth 416 00:37:30,02 --> 00:37:36,92 or this was Earth. This is the snowball earth 417 00:37:37,25 --> 00:37:41,86 or Earth as it looked like six hundred million years ago during 418 00:37:41,87 --> 00:37:45,78 a time period that geologists call the neo proto result like 419 00:37:48,83 --> 00:37:53,87 this is a time before animals and plants this is 420 00:37:53,88 --> 00:37:57,58 a time before trees and dinosaurs but it's not 421 00:37:57,62 --> 00:38:04,32 a time before life and so that's what my talk is about today 422 00:38:04,84 --> 00:38:11,66 is how photosynthetic organisms or photosynthetic algae to be specific 423 00:38:12,02 --> 00:38:18,85 survive that the snowball earth the vents of the neo protozoa So 424 00:38:19,02 --> 00:38:23,100 this is my image of what I think of photosynthetic algae looks like in my brain. 425 00:38:27,91 --> 00:38:34,44 I don't use microscopes so I don't really know. But you might ask why do I care 426 00:38:34,48 --> 00:38:39,95 about algae like they're just what are they well we still have algae around today 427 00:38:40,57 --> 00:38:43,66 but it turns out algae. Have done 428 00:38:43,67 --> 00:38:48,89 a lot of cooling great things in their career how do you want on to evolve into 429 00:38:48,90 --> 00:38:55,66 plants and evolve into trees and this evolution actually 430 00:38:55,67 --> 00:39:01,94 set up the CO evolutionary habitat that allowed for animals like alligators 431 00:39:02,42 --> 00:39:08,47 or the pygmy slaughter or human beings to exist 432 00:39:09,55 --> 00:39:16,14 so to put it another way if it hadn't survived during the 433 00:39:16,15 --> 00:39:22,69 snowball earth then. Plants wouldn't be here and animals wouldn't be here and you 434 00:39:22,70 --> 00:39:28,08 and I would not be here so we really need to understand how these organisms survive 435 00:39:28,09 --> 00:39:35,09 the snowball earth this extremely unique and different 436 00:39:35,10 --> 00:39:38,87 time in the Earth's past so I like to think of this algae as like 437 00:39:38,88 --> 00:39:44,67 a super hero like surviving the extreme events when there was the earth was 438 00:39:44,68 --> 00:39:48,49 a near apocalypse so now you might ask 439 00:39:48,53 --> 00:39:52,88 a little bit about the snowball earth OK this is really weird OK so the earth was 440 00:39:53,09 --> 00:39:58,89 at oceans but they're frozen but they're not completely frozen TELL ME MORE OK Well 441 00:39:59,27 --> 00:40:03,85 first there was the sun but this was really far in the Earth's past this is six 442 00:40:03,86 --> 00:40:08,97 hundred million years ago and to give you some perspective the earth is only about 443 00:40:08,98 --> 00:40:14,08 four point five billion years old and so it's actually so old that the sun was 444 00:40:14,09 --> 00:40:17,42 a little bit dimmer so not quite as bright so things were 445 00:40:17,44 --> 00:40:21,78 a little bit colder to begin with but then the other part of the story comes in is 446 00:40:21,79 --> 00:40:28,61 that there's photosynthetic algae and these these are algae they eat carbon 447 00:40:28,62 --> 00:40:35,60 dioxide and they produce oxygen and I have chosen to represent carbon dioxide as 448 00:40:35,61 --> 00:40:40,68 this very warm mummy bag and I've chosen to represent oxygen as just some thin 449 00:40:40,69 --> 00:40:44,13 sheets that you might get that wouldn't keep you very warm at night and the reason 450 00:40:44,14 --> 00:40:48,49 I'm using This is because carbon dioxide when it's in the atmosphere has the 451 00:40:48,50 --> 00:40:49,57 ability to warm 452 00:40:49,61 --> 00:40:56,32 a planet and oxygen doesn't so if you convert carbon dioxide into 453 00:40:56,33 --> 00:41:01,28 oxygen you're going to cool the planet and it turns out before the snowball earth 454 00:41:01,93 --> 00:41:07,31 these algae were really productive and had lots of offspring and actually were able 455 00:41:07,32 --> 00:41:12,09 to trigger this kind of event so causing the Earth's oceans to be completely frozen 456 00:41:12,10 --> 00:41:18,42 over. So OK so that's really weird how do we get out of this like crazy snowball 457 00:41:18,43 --> 00:41:24,69 that like the Earth's surface is completely covered Well the answer we think is 458 00:41:24,70 --> 00:41:31,70 volcanoes so one thing that's cool about volcanoes is they don't really care if the 459 00:41:31,71 --> 00:41:35,83 earth's surface is covered in ice they don't they don't really care if they pop up 460 00:41:35,87 --> 00:41:39,89 in the tropics or if they pop up in Lascaux they're just going to do their thing 461 00:41:40,40 --> 00:41:47,07 and so one thing that they do is they are wrapped and when they erupt they emit. 462 00:41:48,60 --> 00:41:55,49 And ASH but they also emit gas and one of the gases they emit is carbon dioxide and 463 00:41:55,50 --> 00:42:00,88 so over millions of years during the snowball earth the vents the carbon dioxide is 464 00:42:00,89 --> 00:42:05,65 allowed to build up into the atmosphere doesn't have any place to go and eventually 465 00:42:05,88 --> 00:42:10,43 the carbon dioxide builds up and builds up that it warms the entire planet creating 466 00:42:10,62 --> 00:42:14,60 going from a very very cold planet to an extremely hot planet in just 467 00:42:14,61 --> 00:42:16,76 a few thousand years so that's 468 00:42:16,77 --> 00:42:21,100 a weird planet so where did these things survive during this time and I'm going to 469 00:42:22,07 --> 00:42:27,50 kind of. Pose to you why that's why that's actually difficult answer to get to 470 00:42:28,63 --> 00:42:33,87 so algae need two things to survive during this time they need liquid water has to 471 00:42:33,88 --> 00:42:40,78 be liquid and they need sunlight so liquid water plus sunlight gives you the algae 472 00:42:40,93 --> 00:42:47,64 OK so if we want to understand how we got from a snowball earth to 473 00:42:47,65 --> 00:42:52,19 a present day Earth which is full of life and full of creatures we have to 474 00:42:52,20 --> 00:42:58,97 understand where the photosynthetic algae survived so OK where did they survive 475 00:42:59,86 --> 00:43:05,67 well here's an image of snow and that might be some people's first guess but at the 476 00:43:05,72 --> 00:43:11,30 during the snowball it was below freezing everywhere all the time and so the snow 477 00:43:11,31 --> 00:43:11,81 never had 478 00:43:11,82 --> 00:43:18,65 a chance to melt into liquid water. So they couldn't survive on snow this is 479 00:43:18,66 --> 00:43:19,71 a picture of 480 00:43:19,79 --> 00:43:26,67 a volcanic hotspot that's underneath the ocean OK very warm there these things 481 00:43:26,68 --> 00:43:29,16 would exist during a snowball earth and there's 482 00:43:29,17 --> 00:43:33,53 a lot and there's liquid water plenty of it but there's no sunlight down that deep 483 00:43:33,59 --> 00:43:40,26 so they couldn't survive there either but lakes so lakes of water right yeah OK 484 00:43:40,69 --> 00:43:46,94 and. Why wouldn't they survive there well because either you're in a place on 485 00:43:46,95 --> 00:43:49,72 a snowball where it's snowing all the time or you're at 486 00:43:49,73 --> 00:43:52,25 a place where it's evaporating all the time and if you're 487 00:43:52,26 --> 00:43:54,89 a place where it's snowing all the time well then that Lakes just going to be 488 00:43:54,90 --> 00:43:57,61 filled in the snow and you don't have a lake and if it's 489 00:43:57,62 --> 00:44:01,94 a vaccinating all the time well over the really long time periods the tens of 490 00:44:01,95 --> 00:44:06,03 millions of years these snowballs lasted even the deepest lakes in the world would 491 00:44:06,07 --> 00:44:09,56 eventually just completely dry out so we're going to need 492 00:44:09,57 --> 00:44:15,82 a new idea and so where do the algae survive I don't think that they survived in 493 00:44:15,83 --> 00:44:21,13 Africa but I wanted to point out one thing here I wanted to point out the Red Sea 494 00:44:22,43 --> 00:44:26,99 which is sits between Africa and the Middle East and what I want to point out to 495 00:44:27,00 --> 00:44:32,82 you is that at its southern edge the Red Sea is connected to the ocean but it's 496 00:44:32,83 --> 00:44:33,25 also 497 00:44:33,29 --> 00:44:39,93 a very long and narrow channel that has land on either side of it and 498 00:44:39,94 --> 00:44:44,51 so I'm going to kind of explain to you and I call this kind of feature in Lynn sea 499 00:44:45,26 --> 00:44:48,26 and we expect to see not necessarily the Red Sea during 500 00:44:48,27 --> 00:44:51,34 a snowball earth but we expect to see features like 501 00:44:51,85 --> 00:44:58,81 a Red Sea because of the geologic processes that formed the Red Sea So why do 502 00:44:58,82 --> 00:45:01,43 I think that an inland sea or a narrow channel is 503 00:45:01,44 --> 00:45:06,03 a good place for these photosynthetic organisms to survive well I'm going to try to 504 00:45:06,04 --> 00:45:12,07 convince you that over the next couple slides. So this is an image of what the 505 00:45:12,08 --> 00:45:15,63 continents might have looked like during Snowball Earth so you can see 506 00:45:15,85 --> 00:45:20,85 a couple different things here you can see that you've got land and you also have 507 00:45:21,70 --> 00:45:28,60 ice over the oceans and so like our present day Earth the 508 00:45:29,01 --> 00:45:34,35 the tropics are the equal or is much warmer than the Poles but for 509 00:45:34,36 --> 00:45:39,18 a snowball earth the tropics might be minus thirty degrees Celsius and the Poles 510 00:45:39,19 --> 00:45:45,87 are much much much much colder and so because it's warmer at the tropics 511 00:45:45,92 --> 00:45:50,89 and colder at the poles that creates a hydrologic cycle 512 00:45:50,90 --> 00:45:55,71 a certain hydrologic cycle so at the equatorial have what's called sublimation so 513 00:45:55,75 --> 00:46:01,53 sublimation is the process by which ice solid ice that's covering the ocean is 514 00:46:01,54 --> 00:46:08,30 converted directly into vapor into gas so if you've ever seen dry ice you've 515 00:46:08,31 --> 00:46:12,71 seen sublimation So you've seen that little block of dry ice just it doesn't melt 516 00:46:12,72 --> 00:46:16,95 it doesn't go liquid it just turns into gas that sublimation process and that's 517 00:46:16,96 --> 00:46:19,57 what happened to the ice at the equator during 518 00:46:19,58 --> 00:46:25,67 a snowball earth but that sublimated water will transport to the poles where it is 519 00:46:25,68 --> 00:46:32,34 deposit as ice so what that means is is that because it's colder and there's 520 00:46:32,35 --> 00:46:38,25 snow falling at the poles the ice is really thick there and because it's warmer and 521 00:46:38,26 --> 00:46:42,67 it the ice is supplementing at the tropics or near the equator the ice is is 522 00:46:42,68 --> 00:46:47,29 relatively thin there it's still too thick to allow the light to get through but 523 00:46:47,30 --> 00:46:53,10 it's relatively thin so because you have that slope or that that that 524 00:46:53,51 --> 00:47:00,45 transition from thick ice to thinner ice it actually causes the ice to defy form 525 00:47:00,71 --> 00:47:05,79 and flow under its own weight and that creates rivers of ice that flow from the 526 00:47:05,80 --> 00:47:12,76 poles to the waiter. And so I could kind of draw 527 00:47:12,77 --> 00:47:15,61 on we don't really know where these things might have been but I could kind of draw 528 00:47:15,62 --> 00:47:21,73 on places near the equator or near the tropics where inland seas or these narrow 529 00:47:21,74 --> 00:47:28,17 channels might have existed so why do I think inland seas or narrow channels are 530 00:47:28,18 --> 00:47:32,90 a good place for these things to for algae to survive well I'm going to show you 531 00:47:32,91 --> 00:47:37,88 a series of images and kind of like Megan I'm going to kind of run you through 532 00:47:37,89 --> 00:47:41,91 a on the top is going to be a side view and on the bottom is 533 00:47:41,92 --> 00:47:48,80 a top down view of the same thing so on the top we can see ice that's floating on 534 00:47:48,82 --> 00:47:55,63 water and below that we can see ground and so imagine you have an algae 535 00:47:55,64 --> 00:47:57,12 living down there during 536 00:47:57,13 --> 00:48:01,75 a snowball earth well what's going to happen is that light from the sun 537 00:48:04,67 --> 00:48:09,73 is going to try to make its way through this ice but the ice will end up absorbing 538 00:48:09,74 --> 00:48:13,55 the light and so not enough light will get down there for those photosynthetic 539 00:48:13,89 --> 00:48:20,62 organs for the algae to survive so algae can't survive underneath the ice 540 00:48:20,82 --> 00:48:21,08 during 541 00:48:21,09 --> 00:48:26,06 a snow ball or so if we're near the equator then we're at an area where you have 542 00:48:26,07 --> 00:48:30,78 net sublimation so the ice the solid ice that's on the surface is being converted 543 00:48:30,79 --> 00:48:37,43 or going away into the atmosphere it's turning to gas but you also have these 544 00:48:37,44 --> 00:48:43,78 rivers of ice that are causing the ice to flow so what happens when 545 00:48:43,91 --> 00:48:48,40 a river of ice encounters this kind of narrow channel it goes into this narrow 546 00:48:48,41 --> 00:48:55,15 channel Well it slows down and you can kind of think of this as you know driving on 547 00:48:55,16 --> 00:48:57,89 I five and then all of a sudden there's like 548 00:48:58,21 --> 00:49:00,57 a big wreck and then you're down to one lane of traffic all of 549 00:49:00,58 --> 00:49:05,44 a sudden things get slow when you get compressed and so this this ice that's 550 00:49:05,45 --> 00:49:07,58 flowing through here will slow down as 551 00:49:07,59 --> 00:49:13,68 a result of that but at the same time as it's being as it's slowing down it's also 552 00:49:13,72 --> 00:49:18,64 being sublimated away so it's just leaving it's leaving go to go to the atmosphere 553 00:49:18,64 --> 00:49:24,26 . So if that channel that narrow channel is long enough then eventually there just 554 00:49:24,27 --> 00:49:30,15 won't be any ice left so if you were on this slow freeway and there were only 555 00:49:30,16 --> 00:49:34,10 places to get off the freeway but not to get on that eventually you're going to 556 00:49:34,11 --> 00:49:34,28 reach 557 00:49:34,29 --> 00:49:38,17 a point there for you where there are there's just no more cars anymore so it's 558 00:49:38,18 --> 00:49:44,85 kind of like that and so in this place where the ice that's covered the ocean can't 559 00:49:44,86 --> 00:49:46,89 reach that is 560 00:49:46,90 --> 00:49:51,20 a location where these photosynthetic organisms could survive during the snowball 561 00:49:51,21 --> 00:49:57,92 or the vents so here's an image of what the Red Sea looks like and again this isn't 562 00:49:57,96 --> 00:50:02,79 a real the Red Sea didn't exist during the snowball at the vents but we think that 563 00:50:02,80 --> 00:50:09,32 places like it may have existed because the geologic processes that formed the Red 564 00:50:09,33 --> 00:50:14,60 Sea were also present during the snowball earth events and so if you do 565 00:50:14,61 --> 00:50:20,41 a calculation which is my research to calculate how far ice coming from the 566 00:50:20,42 --> 00:50:26,35 southern end into the Red Sea would actually travel into that into that sea given 567 00:50:26,36 --> 00:50:32,12 the the climate that we know like how fast the ice is is flowing and how how fast 568 00:50:32,13 --> 00:50:37,43 the ice is sublimating away how fast it's being removed then what we find is that 569 00:50:37,44 --> 00:50:40,36 under certain conditions it allows for 570 00:50:40,37 --> 00:50:45,07 a little pocket of of water to remain that us that the ice that's covering the 571 00:50:45,08 --> 00:50:49,03 ocean doesn't get to and so that's 572 00:50:49,04 --> 00:50:54,15 a place where these photosynthetic organisms could have survived and lived 573 00:50:54,35 --> 00:51:01,30 throughout the entire snowball or the bends so again if we want to look at 574 00:51:01,75 --> 00:51:08,14 Earth today and understand the and appreciate the the diversity of life around us 575 00:51:08,15 --> 00:51:13,76 and appreciate our own existence we really have to think these algae for surviving 576 00:51:13,77 --> 00:51:19,33 during this novel or the vent because life as we know it wouldn't exist today if it 577 00:51:19,34 --> 00:51:23,76 weren't for these photosynthetic organisms. So I kind of want to end with 578 00:51:24,31 --> 00:51:30,86 a picture of Earth from space the one I started off with because I think that if 579 00:51:30,87 --> 00:51:34,14 you look at if you were if you were on another planet and you were looking at Earth 580 00:51:34,15 --> 00:51:38,63 right now with all of its different life and just and all of its diversity you 581 00:51:38,64 --> 00:51:39,47 would say hey there's 582 00:51:39,48 --> 00:51:43,83 a planet that has life on it for sure but if you were to look at Earth six hundred 583 00:51:43,84 --> 00:51:47,66 million years ago during the snowball earth you would probably say that it was 584 00:51:47,67 --> 00:51:53,17 a dead planet but so consider that when we're looking out of the stars and we look 585 00:51:53,18 --> 00:51:57,99 at some of these strange planets that there might actually be life surviving the 586 00:51:58,00 --> 00:52:02,32 seeds of life surviving and getting by in these nooks and crannies in these little 587 00:52:02,33 --> 00:52:07,53 tiny spots just waiting to flourish when the climate changes all right thank you 588 00:52:07,54 --> 00:52:12,76 very much I'll take your questions. Thank you. 589 00:52:15,85 --> 00:52:22,18 OK question. Could you explain why the ice would sublimate rather than turn into 590 00:52:22,19 --> 00:52:26,61 liquid was it just too cold for the liquid it would just some of it would just turn 591 00:52:26,62 --> 00:52:32,35 to get this yeah so so the idea is that the surface temperatures are never warm 592 00:52:32,36 --> 00:52:37,86 enough to actually melt it but they're happening because there's just wind in 593 00:52:37,87 --> 00:52:42,82 things that will cause the ice to go into the atmosphere so it's never it has you 594 00:52:42,83 --> 00:52:47,63 have to get above freezing to have melting but you don't have to get above freezing 595 00:52:47,64 --> 00:52:52,35 to have sublimation. Since life existed in the earth for several billion years 596 00:52:52,36 --> 00:52:58,17 before snowball earth with the other Snowball Earth yeah so that's 597 00:52:58,18 --> 00:53:02,54 a great question so during the protozoa at the time that I was talking about like 598 00:53:02,55 --> 00:53:08,18 six hundred million years ago there we think there were at least two Snowball Earth 599 00:53:08,19 --> 00:53:12,84 events with there's evidence for maybe two more other than that during that same 600 00:53:12,85 --> 00:53:19,36 time period plus there's evidence for another snowball earth that happened. Way 601 00:53:19,37 --> 00:53:20,42 back in Earth's past like 602 00:53:20,46 --> 00:53:25,54 a couple billion years ago but that was before these kind of organisms existed at 603 00:53:25,55 --> 00:53:28,30 all so yeah so it's happened 604 00:53:28,31 --> 00:53:38,47 a few times it looks like. So 605 00:53:38,95 --> 00:53:43,67 six hundred million years ago that was animal life right no no they think there 606 00:53:43,68 --> 00:53:50,40 might have been sponges. And so they survived yeah they have they had Yeah 607 00:53:50,66 --> 00:53:55,99 they would have and so yeah there's those those kind of those so the photosynthetic 608 00:53:56,00 --> 00:54:00,86 Henri's are really the what went on to make this is before plants for animals they 609 00:54:00,87 --> 00:54:07,45 were like there's some evidence for sponges but it's I think that as far as it goes 610 00:54:07,46 --> 00:54:11,68 that algae are really the most complicated lifeforms that existed during this time 611 00:54:11,68 --> 00:54:18,62 . This noble or earth was 612 00:54:18,63 --> 00:54:21,46 shortly before the Cambrian explosion you know there's 613 00:54:21,47 --> 00:54:28,27 a huge speciation and the evolution of lots of diverse life the first one as I 614 00:54:28,28 --> 00:54:33,89 understand it is two point two billion years ago and from what I've read. Shortly 615 00:54:33,90 --> 00:54:40,87 there after cells within. The vault What is it about the 616 00:54:40,88 --> 00:54:47,12 limitations of life that causes huge speciation and quick evolution afterwards yeah 617 00:54:47,13 --> 00:54:47,37 that's 618 00:54:47,38 --> 00:54:53,94 a really good question that I am completely on A quick to answer given my background 619 00:54:53,94 --> 00:54:59,94 . So my my background is actually in Clichy ology so studying how I split was so 620 00:54:59,96 --> 00:55:01,26 you can see why it's noble or it might be 621 00:55:01,26 --> 00:55:06,67 a novel problems me but when it comes to evolutionary biology I you know I have 622 00:55:06,67 --> 00:55:08,19 a very fundamental 623 00:55:08,73 --> 00:55:14,90 a very fundamental understanding of it but not super technical so I mean but as far 624 00:55:14,92 --> 00:55:19,22 as I know these are questions that people are still trying to answer like why do we 625 00:55:19,23 --> 00:55:23,68 have this great diversity after these near catastrophes and I think it's really 626 00:55:23,68 --> 00:55:30,63 unresolved as far as I know so. OK last 627 00:55:30,64 --> 00:55:36,15 question. Well that's good because that was my first last question all right. 628 00:55:37,73 --> 00:55:39,08 You said it it ended in 629 00:55:39,09 --> 00:55:45,97 a thousand years that didn't make any sense to me. When you have they have to build 630 00:55:45,98 --> 00:55:46,67 up oh yeah 631 00:55:46,68 --> 00:55:51,77 a long period of time yeah I must have misspoken I meant to say tens of millions of 632 00:55:51,78 --> 00:55:58,50 years yeah so. I'm sorry you know. And perhaps I 633 00:55:58,51 --> 00:55:59,11 misheard I'm 634 00:55:59,12 --> 00:56:05,76 a little deaf. There are organisms that live in snow Arthur bunch of other 635 00:56:05,77 --> 00:56:12,16 places for life to survive rather than in liquid water yeah so animals presently do 636 00:56:12,17 --> 00:56:17,89 survive in snow but it's no that does eventually get above melting occasionally and 637 00:56:18,37 --> 00:56:22,14 this during the snowball earth we don't think that that every or no photo 638 00:56:22,15 --> 00:56:27,24 synthesizers that exist in snow there are but it's places where it occasionally 639 00:56:27,25 --> 00:56:33,01 gets above melting and you can have liquid water so yeah that it's 640 00:56:33,02 --> 00:56:36,34 a particular kind and photosynthetic it's 641 00:56:36,35 --> 00:56:40,23 a particular kind of photosynthetic algae and so if I can get 642 00:56:40,24 --> 00:56:43,77 a little more deeper in the problem idea of the snowball earth is not like 643 00:56:44,78 --> 00:56:49,04 scientists are still debating whether or not it happened and biologists are 644 00:56:49,05 --> 00:56:53,54 actually people who are saying snowball earth couldn't have happened because 645 00:56:53,79 --> 00:56:59,18 there's no environment for which them to survive so the onus is on geologists like 646 00:56:59,19 --> 00:57:03,03 myself to kind of try and find these environments where they could have survived 647 00:57:03,07 --> 00:57:07,34 icy are are you imagining that these are blue green algae or so yeah so there's 648 00:57:07,35 --> 00:57:11,69 different blue green algae is the specific kind Yeah thank you yeah all right thank 649 00:57:11,70 --> 00:57:12,29 you very much.